Strategic Vinyl Sulfone Nucleophile β-Substitution Significantly Impacts Selectivity in Vinylogous Darzens and Aza-Darzens Reactions
作者:Michael D. Delost、Jon T. Njardarson
DOI:10.1021/acs.orglett.0c02448
日期:2020.9.4
employing a benzothiophene 1,1-dioxide nucleophile are reported. These new [2 + 1] annulation reactions, which proceed under mild reaction conditions, are γ-selective, affording trans-epoxides selectively and favoring trans-aziridines. The reactions are base-dependent, with KOtBu and Cs2CO3 being optimal for aldehyde and imine annulations, respectively. Comparison of the benzothiophene nucleophile to its acyclic
报道了使用苯并噻吩1,1-二氧化物亲核试剂的酒状Darzens和氮杂-Darzens反应。这些在温和的反应条件下进行的新的[2 +1]环化反应具有γ选择性,可选择性提供反式环氧化物,并有利于反式氮丙啶。该反应是碱依赖性的,其中KOtBu和Cs 2 CO 3分别对于醛和亚胺环化而言是最佳的。苯并噻吩亲核体与其无环对应物的比较显示出在醛类情况下的优越性能,而结果则取决于所用的磺酰胺亚胺。